Many premature newborn infants have difficulty manufacturing a sufficient number of white blood cells to protect them from infection. This results in a high incidence of infectious complications mary: affecting premature newborns in newborn intensive care units. This study was designed to determine if a factor that stimulates the bone marrow to make more white blood cells (granulocyte colony-stimulating factor or G-CSF) could be effective in raising the white blood cell count of premature neonates, and thereby protecting them from infectious disorders.